Polymers with their use in pharmaceutics. Approaches in designing of control drug release delivery system. Classification of polymers according to their use in pharmacy field with their use in various use in dosage form development.

1. POLYMERS IN PHARMACY
By-
Prof. Vedanshu Malviya
(M.Pharm-Pharmaceutics)
P.R. Pote Patil college of Pharmacy, Amravati

2. INTRODUCTION
• The word “Polymer” is derived from two Greek words, ‘Poly’ that means many
(numerous) and ‘Mer’ which means units.
• Polymer have played indispensable roles in the preparation of pharmaceutical
products. Their applications range widely from material packaging to fabrication
of the most sophisticated drug delivery devices. This review includes various
polymers used in pharmaceutics based on their applications.
• Polymers are long chain organic molecules assembled from many smaller
molecules called as monomer.
• The use of polymers for biomedical and pharmaceutical applications has gained
an enormous impact during the past decades.

3. IDEAL CHARACTERISTICS
• It should be inert and compatible with the environment.
• It should be non- toxic and physiologically inert.
• It should be easily administrable.
• It should be easy to fabricate and must be inexpensive.
• It should have good mechanical strength.
• It must have compatibility with most of the drugs.
• It must not adversely affect the rate of release of the drug.
• It must not have tendency to retain in tissue and must be a good biodegradable
material.

4. ADVANTAGES
• The polymer have been synthesized for specific need and to solve problems
related with development of drug delivery system.
• Polymers have been mainly used to control the drug release rate from the
formulations as well as a taste masking agent, stabilizer and protective agent in
oral drug delivery.
• Polymers can bind the particles of a solid dosage form and also change the flow
properties of a liquid dosage form.
• Polymers are macromolecules having very large chains contain a variety of
functional groups, can be blended with other low and high molecular weight
material.
• Polymers are mostly applied in drug delivery because they have unique properties
which have not been attained by any other material.

5. CONT…
• In development of drug delivery/targeting technique to improve the efficiency of
drug therapy.
• In development of new technology in polymer based encapsulation and controlled
drug release system.
• To minimize side effect in medical treatment.
• In pharmaceutical field polymer used as binder, emulsifying agent, thickening agent
etc.
• Polymer also used as film coating to masking the unpleasant taste to enhance drug
stability and in protection and packaging.

6. CLASSIFICATION
• Classification of polymer depends upon various factors like solubility, source,
stability, chemical nature, chemical bonds, applications.
• Many polymers and their classes are used in various fields. Like plumbing,
electrical, construction, automobile, and etc.
• Here we will discuss about the various sources related only with pharmaceutical
field in greater context with the use of polymers in the manufacturing of the
control drug release dosage forms.
• Following is the classification system of polymer related only with the
pharmaceutical field.

7. Polymer
Based on origin
Natural Synthetic
Based on Bio-
stability
Bio-degradable Non- Bio degradable
Based on Solubility
Water Soluble Water Insoluble
Classification of Polymers

8. CLASSIFICATION
• A. Based on origin
• a) Natural polymer
• Natural polymers are the substances which are obtained by natural sources like
plant and animal sources.
• Proteins, enzymes, muscle fibers, polymer polysaccharide, gummy exudates are
the natural polymers which are used in formulating pharmaceutical products.
• The well-known natural polymers are chitosan, carrageenan, isapghula, acacia,
gelatin, agar, shellac, guar gum.
• The specific application of plant derived polymer in pharmaceutical formulations
include their use in the manufacture of solid monolithic matrix systems, implants,
films, beads, micro particles, nanoparticles, inhalable and injectable system as well
as viscous liquid formulations.
• E.g. Proteins-collagen, keratin, albumin

9. CONT…
b) Synthetic polymer
• Synthetic polymers are industrially produced chemical substances consisting of a
number of molecules linked together with covalent bond.
• A wide variety of synthetic polymers are available with variation in main chain as
well as side chain.
• The most commonly used synthetic polymer are polythene and polystyrene.
• E.g. polyester, polyanhydrides, polyamides, polyglycolic acid.

10. B) BASED ON BIO-STABILITY
A) BIO-DEGRADABLE POLYMERS
• A bio-degradable polymer is a polymer in which the degradation results from the
action of naturally occurring microorganisms such as bacteria, fungi.
• Biodegradable polymers are highly desirable in their conditions as they degrade in
the body to biologically inert and compatible molecules.
• These polymer includes polyester, proteins, carbohydrates, etc.

11. CONT…
b) Non-biodegradable polymer:
• This polymers are used in pharmaceutical formulation to increase the therapeutic
efficacy of drug.
• This polymers is now days used in drug delivery system and tissue engineering.
• Following are the non-biodegradable polymers used in pharmaceutical formulation-
E.g. ethyl cellulose, HPMC, acrylic polymer, poly (ethylene glycol).

12. C) BASED ON SOLUBILITY
• a) Water Soluble:
• These are the polymers which are soluble in water after the swelling behaviour
of the polymer. i.e. after the polymer absorbs the water upto its capacity the
polymer begins to swell and after that it gets dissolved.
• Some of these kind of polymer may be easily water soluble but some may
require the application of heat to get dissolved.
• These kind of polymers are usually used in the application of gelling system,
SRDDS, to change the rheological property, etc.
• Examples include: HPMC, Carragenan, PVA, Gellan gum, Carbopol, Pullulan, etc.

13. CONT…
• b) Water-Insoluble Polymers:
• The kind of polymers are not having the aqueous solubility some of them are having
the swelling property i.e. the polymer is not water soluble but it is swellable.
• These kind of polymer get their use in the application of mostly in the SRDDS
having the porous nature or microporous nature type of DDS. (e.g. Transdermal
Patches, Microspheres, etc.)
• Examples include: Ethyl-Cellulose, Eudragit, Acrylic Polymers, Curdlan, etc.

14. APPLICATION OF POLYMERS IN CONTROL DRUG
DELIVERY SYSTEM
• Controlled release formulations attempt to alter drug absorption and
subsequent drug concentration in blood by modifying the drug release rate
from the device.
• Polymer use in controlled release dosage is reduced fluctuations in the plasma
drug concentration, less side effects, and increased patient compliance.
• Controlled release products consist of the active agent and the polymer matrix
or membranes that regulate its release.
• Advances in controlled release technology in recent years have been possible as
a result of advances in polymer science that allow the fabrication of polymers
with tailor-made specific cations, charge density, such as molecular size, specific
functional groups, hydrophobicity, biocompatibility, and degradability.
• Progress in the area of controlled drug delivery has been possible only as a
result of the incorporation of polymer science into pharmaceutics.

15. CONT…
• Controlled release dosage forms refresh old drugs by reducing pharmaceutical
shortcomings and improving biopharmaceutical properties of the drugs.
• Polymers used in controlled release dosage forms are an alternative to the
development of new drugs, which is extremely costly. The controlled release
dosage forms are also important in the delivery of newly developed protein
drugs.
• Examples: Use of Ethyl cellulose in the manufacturing of Microspheres.

16. INSTANCE OF DRUG RELEASE FROM
TABLET
• In the figure graph we can see that the drug release from the tablet is maintained in
a sustained manner with the use of polymer for upto 12 hours of time period.
• It showed that as the polymer layer gets dissolved or the fluid enters through the
porous membrane the drug gets started to release from the formulation and it gets
available to the body for absorption.
• While in the second case we can see that when there is no use of polymer in the
formulation the drug gets faster release rate and it shows no sustained manner and
the whole amount of drug is release within a short period of time i.e. it cannot
sustain the release rate for more than 6 hours of time period.

17. FIGURE OF % DRUG RELEASE FROM
TABLET
0
20
40
60
80
100
120
0 2 4 6 8 10 12 14
%DRUGRELEASE
TIME
% Drug Releae from Tablet
Drug Release with Polymer Drug Release without Polymer

18. REFERENCE
• M.J.D. Eenink et al., Biodegradable Hollow Fibres For The Controlled Release Of
Hormones, J.Controlled Release 6; page. No. 225-247, 1987.
• Ramtoola Z, Corrigan OI And Barreyy CJ: Release Kinetics Of Fluphenazine From
Biodegradable Microspheres, J.Microencapsule9; page. No. 415-423, 1992.
• Nair Lakshmi S., Laurencin Cato T., “Polymers as Biomaterials for Tissue Engineering and
Controlled Drug Delivery” Book: Tissue Engineering I Publisher: Springer Berlin /
Heidelberg, page. No 203-210, 2006.
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terpolymer bearing furan rings as pendant groups. J. Macromol. Sci.
• A 2012, 49 (8), 655–665. 83. Chauhan, N.P.S.; Ameta, S.C. Preparation and thermal studies
of self-crosslinked terpolymer derived from 4-acetylpyridine oxime, formaldehyde and
acetophenone. Polym. Degrad. Stabil. 2011, 96 (8), 1420–1429. 84.
• Chauhan, N.P.S. Isoconversional curing and degradation kinetics study of self-assembled
thermo-responsive resin system bearing oxime and iminium groups. J. Macromol. Sci. A
2012, 49 (9), 706–719.